From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: None (no SPF record) identity=mailfrom; client-ip=83.163.83.176; helo=sibelius.xs4all.nl; envelope-from=mark.kettenis@sibelius.xs4all.nl; receiver=edk2-devel@lists.01.org Received: from sibelius.xs4all.nl (sibelius.xs4all.nl [83.163.83.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 869BA211A1E3D for ; Sat, 12 Jan 2019 10:25:29 -0800 (PST) Received: from localhost (bloch.sibelius.xs4all.nl [local]) by bloch.sibelius.xs4all.nl (OpenSMTPD) with ESMTPA id 2b0677a3; Sat, 12 Jan 2019 19:18:46 +0100 (CET) Date: Sat, 12 Jan 2019 19:18:46 +0100 (CET) From: Mark Kettenis To: Leif Lindholm CC: ard.biesheuvel@linaro.org, edk2-devel@lists.01.org In-reply-to: <20190111175844.cvxsze74xylv7s3s@bivouac.eciton.net> (message from Leif Lindholm on Fri, 11 Jan 2019 17:58:44 +0000) References: <20181226132530.8445-1-ard.biesheuvel@linaro.org> <20181226132530.8445-4-ard.biesheuvel@linaro.org> <20190111175844.cvxsze74xylv7s3s@bivouac.eciton.net> Message-ID: <9e5d26f9f11c5929@bloch.sibelius.xs4all.nl> Subject: Re: [PATCH edk2-platforms 3/3] Silicon/SynQuacer: add support for DEBUG output on second UART X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 12 Jan 2019 18:25:30 -0000 > Date: Fri, 11 Jan 2019 17:58:44 +0000 > From: Leif Lindholm > > On Wed, Dec 26, 2018 at 02:25:30PM +0100, Ard Biesheuvel wrote: > > On headless server systems where the PL011 serial port is the primary > > console, having DEBUG output on the same port can be annoying, since > > DEBUG output gets lost when the console driver clears the screen or > > positions the cursor using control characters. > > > > So add the ability to emit the DEBUG output on the DesignWare FUART > > (which is exposed via the LS connector on DeveloperBox) > > >From what I can tell, the DesignWare component is 8250-compatible, yet > here we're using the 16550 driver. I presume this makes no difference > for how we're using it, but could you add a comment to this effect to > the commit message? (If the FUART is indeed a 16550 clone, please add > a statement to that effect instead.) The DesignWare component is (largely) 16550-compatible. But the FIFO's are optional and if they're not included you'll end up with something that's probably closer to an 16450. I suspect in most cases SoC designers will include the FIFO's though since without them you really can't use the port at anything but the slowest speeds. Cheers, Mark